Preparation of Affinity Membrane for Protein Recovery

将甲基丙烯酸缩水甘油酯辐射接枝到聚乙烯微滤中空纤维上，然后将生成的环氧化物与L-苯丙氨酸偶联，制得了以L-苯丙氨酸为假生物特异性配体的中空纤维膜。剩余的环氧基团用硫酸水解成二醇基团。L-苯丙氨酸和二醇基团分别作为假生物专一性配体和亲水性基团起互补作用。多孔性吸附剂对牛丙种球蛋白的吸附能力可以由其比表面积来决定。通过辐射接枝甲基丙烯酸缩水甘油酯，然后与苯丙氨酸(Phe)或色氨酸(Trp)偶联，制备了一种以疏水氨基酸为配体的中空纤维亲和膜。所得亲和膜的苯丙氨酸和色氨酸配基密度分别为0.4和0.4摩尔/公斤。含Trp的亲和膜比含Phe的亲和膜具有更高的牛血清白蛋白(BGG)吸附量。为了评价膜的吸附行为，将含有BGG的缓冲液从内到外通过配基固定的孔渗透到含Trp的中空纤维亲和膜上。穿透曲线与出水体积的函数关系是一致的，与流量无关，即溶液在膜(厚度0.83 mm)上的停留时间(55-220 S)是可以忽略的传质阻力的结果。经过吸附-洗涤-洗脱等一系列的层析过程，得到了满意的定量洗脱效果。通量和蛋白质浓度的可重复性确保了使用含有色氨酸的亲和膜作为配基的定量层析循环。

A porous hollow-fibre membrane containing L-phenylalanine as a pseudo-biospecific ligand has been prepared by radiation induced grafting of glycidyl methacrylate onto polyethylene microfiltration hollow fibre, followed by coupling of the produced epoxide group with L-phenylalanine. The remaining epoxide group was hydrolysed into a diol group with sulphuric acid. The L-phenylalanine and the diol group acted in a complementary way as a pseudo-biospecific ligand and a hydrophilic group, respectively. The adsorption capacity of bovine gamma globulin on the resulting porous adsorbent could be determined by the specific surface area of the adsorbent when the ligand was in excess over the protein.A hollow-fibre affinity membrane containing hydrophobic amino acids as ligands was prepared by the radiation-induced grafting of glycidyl methacrylate onto a porous polyethylene hollow fibre and subsequent coupling with phenylalanine (Phe) or tryptophan (Trp). The densities of the Phe and Trp ligand of the resulting affinity membrane were 0.4 and 0.4 mol/kg, respectively. The Trp-containing affinity membrane exhibited a higher amount of adsorbed bovine y-globulin (BGG) than the Phe-containing membrane. To evaluate the adsorption behavior of the membrane, the BGG-containing buffer solution was permeated from the inside to the outside of the Trp-containing hollow-fibre affinity membrane through the ligand-immobilized pores. The breakthrough curves as a function of effluent volume coincided irrespective of the flow-rate, i.e. the residence time (55-220 s) of the solution across the membrane (thickness 0.83 mm), as a result of negligible mass transfer resistance. A series of chromatographic procedures, (adsorption-washing-elution) was repeated twice and a satisfactory quantitative elution was attained. The reproducible profile of the flux and the protein concentration assured a quantitative cycle of chromatography using the affinity membrane containing Trp as a ligand.